The present invention relates generally to a new polypeptide having diagnostic and therapeutic uses. In particular, the present invention relates to a novel tumor marker, designated xe2x80x9cZsig62,xe2x80x9d and to nucleic acid molecules encoding Zsig62.
Cancer is a complex disease, often having a mixed etiology. Although environmental factors appear to play a dominant role in the development of certain cancers, it is also clear that genetic factors determine cancer susceptibility (for a review, see Cornelisse and Devilee, Patient Education and Counseling 32:9 (1997), Brandt-Rauf and Pincus, Pharmacol. Ther. 77:135 (1998), and Jameson, xe2x80x9cOncogenes and Tumor Suppressor Genes,xe2x80x9d in Principles of Molecular Medicine, Jameson (ed.), pages 73-82 (Humana Press, Inc. 1998)). Genetic changes can affect many aspects of cellular function, such as an increased rate of cellular proliferation, resistance to apoptosis, altered tissue invasiveness, production of growth and angiogenic factors, and the ability to avoid immune defenses.
For example, genetic alterations of oncogenes and tumor suppressor genes can be identified in a variety of human tumor tissues. Upon abnormal activation, the so-called xe2x80x9cproto-oncogenesxe2x80x9d can induce uncontrolled cellular proliferation. The products of proto-oncogenes include extracellular growth factors, transmembrane growth factor receptors, components of intracellular signal pathways, and components of the system that drives the cell division cycle and cellular self-destruction.
While proto-oncogenes are dominantly-acting genes, tumor suppressor genes act in a recessive manner. That is, both copies of a tumor suppressor gene must be inactivated to induce tumor growth. The inactivating mutations may be inherited in the germline, acquired by somatic mutation, or acquired by a combination of these events. The end result is that, when mutations inactivate both copies of tumor suppressor genes, normal inhibition of cellular growth is lost. Tumor suppressor genes include sequences that encode proteins involved in transcriptional regulation, cell cycle progression, and signaling pathways.
In certain cases, alterations in tumor suppressor genes are believed to occur early in the process of carcinogenesis and to be correlated with a subsequent development of cancer. The detection of such alterations would provide useful molecular markers for diagnosis, surveillance, early tumor identification and intervention, and prognosis. Yet the initial identification of a new tumor suppressor gene marker is difficult because mutations in these genes act recessively at the cellular level.
A need therefore exists for the identification of tumor suppressor genes that are involved in hereditary cancer syndromes.
The present invention provides a novel gene, designated xe2x80x9cZsig62.xe2x80x9d The present invention also provides Zsig62 polypeptides and Zsig62 fusion proteins, nucleic acid molecules encoding such polypeptides and proteins, and methods for using these amino acid and nucleotide sequences.